How to find a bug in application? Tips and Tricks

A very good and important point. Right? If you are a software tester or a QA engineer then you must be thinking every minute to find a bug in an application. And you should be!

I think finding a blocker bug like any system crash is often rewarding! No I don’t think like that. You should try to find out the bugs that are most difficult to find and those always misleads users.

Finding such a subtle bugs is most challenging work and it gives you satisfaction of your work. Also it should be rewarded by seniors. I will share my experience of one such subtle bug that was not only difficult to catch but was difficult to reproduce also.
I was testing one module from my search engine project. I do most of the activities of this project manually as it is a bit complex to automate. That module consist of traffic and revenue stats of different affiliates and advertisers. So testing such a reports is always a difficult task. When I tested this report it was showing the data accurately processed for some time but when tried to test again after some time it was showing misleading results. It was strange and confusing to see the results.

There was a cron (cron is a automated script that runs after specified time or condition) to process the log files and update the database. Such multiple crons are running on log files and DB to synchronize the total data. There were two crons running on one table with some time intervals. There was a column in table that was getting overwritten by other cron making some data inconsistency. It took us long time to figure out the problem due to the vast DB processes and different crons.

My point is try to find out the hidden bugs in the system that might occur for special conditions and causes strong impact on the system. You can find such a bugs with some tips and tricks.

So what are those tips:

1) Understand the whole application or module in depth before starting the testing.

2) Prepare good test cases before start to testing. I mean give stress on the functional test cases which includes major risk of the application.

3) Create a sufficient test data before tests, this data set include the test case conditions and also the database records if you are going to test DB related application.

4) Perform repeated tests with different test environment.

5) Try to find out the result pattern and then compare your results with those patterns.

------------

6) When you think that you have completed most of the test conditions and when you think you are tired somewhat then do some monkey testing.

7) Use your previous test data pattern to analyse the current set of tests.

8) Try some standard test cases for which you found the bugs in some different application. Like if you are testing input text box try inserting some html tags as the inputs and see the output on display page.

9) Last and the best trick is try very hard to find the bug ;-) As if you are testing only to break the application!

I will include more tips in some coming posts.

Meantime you can comment out more tips here.



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98 comments ↓

#1 Vijay on 06.22.07 at 11:06 am

Ya Debasis I agree , you can’t do anything without passion..

#2 Maverick on 06.25.07 at 4:28 pm

Out of box thinking is a must for software tester!

#3 Sameer S. mandve on 07.04.07 at 6:00 am

Please share some actual practices, cases or examples so that we ‘ll get better Idea.

#4 Vijay on 07.04.07 at 7:09 am

Hi Sameer,
I mentioned one of my testing experiences in above post.
Here I will share one more experience which is related to the how should tester think while testing?
In one of my appraisal form my manager commented one line as “Wear cap of different users while testing respective modules”.
It taught me lot of things.
Tester should think all the effects of the particular updated module. In my web project there were different modules like Advertiser stats pages, related admin pages, related advertiser-Partner pages. So as a case when any of the page or module get updated you should think the effect of that on all other pages even they are on different domains (In case of web testing).

Will keep on adding such practical cases as and when possible.

#5 jhenz on 07.26.07 at 8:48 am

yes, i agree on this… “you should think the effect of that on all other pages even they are on different domains (In case of web testing).”, this is what we call system testing. making sure that all modules (as a group) function appropriately, given the updates of one particular module. :D

#6 Naga Vishala on 08.28.07 at 6:31 pm

Hello, i faced one question in the interview that was

How can you say that these many test cases are enough for the particular Object or Field?

can u plz tell me what should be the answer.

#7 Vijay on 09.03.07 at 8:37 am

@ Naga Vishala – Actually application coverage should not be measured on number of test cases. The answer should be like this, you should possibly write the smallest set of test cases those will uncover all possible errors in application. You can measure coverage from all possible paths. You can say almost all test cases are covered when you are sure that your test cases combination is covering all the possible paths in the application.

#8 seetha on 10.23.07 at 1:27 pm

Hi All,

Can some one help me how to test a memory leak in a application?

#9 AAYUSH on 10.25.07 at 9:48 am

Please guide me on this, I am an MBA having 3+ years of experience in sales administration with leading MNC’s in India. But somehow I got the chance to join a IT MNC as sr. software tester, Its been six months and things are going fine till now,
I should I shape up my career from here. Is testing right option for me,
How can I get into sales in IT from here

Plz guide

#10 AAYUSH on 10.25.07 at 9:50 am

Please guide me on this, I am an MBA having 3+ years of experience in sales administration with leading MNC’s in India. But somehow I got the chance to join a IT MNC as sr. software tester, Its been six months and things are going fine till now,
I should I shape up my career from here. Is testing right option for me,fhgt
How can I get into sales in IT from here

Plz guide

#11 Charu on 10.31.07 at 1:40 pm

I hae just started to read the articles in this site. Ver nice and very helpful. Thanks.

#12 Pavani on 12.17.07 at 10:01 am

hi Vijay

I have read some articles from ur site,which were very helpful..thank u

Can u suggest how to create sufficient test data for test cases with an example and what are the various procedures followed in realtime for creating test data?

thank u

#13 kalyan on 12.20.07 at 1:06 pm

hii my name is kalyan.

i joined in ac company as software tester.can u tell me in general how the testing process.i want real time answer,bocs which we read from material is differ from real time.

#14 kalyan kumar on 12.20.07 at 1:09 pm

i have recently joined in small company.we got project.it should be handle by me alone.

can any body tell.how should i start and how will be testing process in real time. which i read from material will be differ from real time testing .pls any body will help me

#15 kalyan on 12.21.07 at 7:17 am

pls send reply to my mail id ajaykumar.net@gmail.com

or funajju@gmail.com

#16 Laxmikanth on 12.26.07 at 11:22 am

Hello
Can anyone pls tell me ‘hwz career in testing?, i am basically a Mechanical engineer but i got into a software company thinking tat i ll be put up in java development i joined the copm as i have did java course then i was put up in testing. frm past 11 months me in testing. so am in dilemma weather to continue the job or quit it. pls do suggest me i ll be very kind full..
my email ID lktkar2002@yahoo.co.in
Regards
Laxmikanth

#17 Software Testing Help: Best software testing articles of 2007 on 01.07.08 at 12:24 pm

[...] How to find a bug in application? Tips and Tricks [...]

#18 Ravi on 01.31.08 at 8:02 pm

HI all here is my suggestion, Testing is the carrer which should build with innovative thinking this comes with exp. My Experience Testcases, Testdata are the start up for u to get into process of knowning things i.e getting familier with the application but on the hole a testing with unknown data which is dynamic will really caught the application bugs. Freshers never worry how is it done u get to know when u are in. But to get in u should have Knowledge on what is testing and all the models in depth with manual testing concepts.

#19 Prabhu Dev on 03.18.08 at 8:38 am

I have changed my professioanl from Sys admin to testing now I am able to enjoy the challenge, but my next step I am looking forward to do some developing but I am feeling it is unsecured and it is very hardone for me, can any one suggest me some thing on this.

#20 RahulKumar on 03.18.08 at 10:24 am

@Laxmikanth
hi Testing field is very emerging .let me tell you reason..see market treand is changing now sa day..sometimes Java was at pick now .net in future sometihing elss suppode xx language ..But what ever will be situation TESTING will be inevitable so never warried ..Concentrate on work..Love your work dont love company…remember com.stops loving at any time..
cheers
RahulKumar

#21 RahulKumar on 03.18.08 at 10:37 am

@Pavani
Could some1 answew Pavani Question .It seems really good question.
.hi Vijay

I have read some articles from ur site,which were very helpful..thank u

Can u suggest how to create sufficient test data for test cases with an example and what are the various procedures followed in realtime for creating test data?

thank u

#22 Vishal on 03.19.08 at 10:30 am

Hi Sir,

I am trying to break the application by entering special characters, etc etc….. but m not able to break the code for Php or .Net application. Can u please suggest some tricks for this.

#23 susan on 04.10.08 at 6:18 am

@Vishal
Try these very special charecters ????
cheers…
susan

#24 susan on 04.10.08 at 6:23 am

Hey its not supporting what i have typed is symbol Diamond, Clubs, Spade, Hearts

#25 Norman on 04.16.08 at 8:10 pm

Iam not able to understand what is this APACHE AND TOMCAT SERVER is all about..are they different ?
Some say they are not and they are called as webapplication servers.By the way do application server and web server reside on the same machine or in different machines.How they are configured.
How a application server contacts webserver or vice versa..again are they configured on differnet machines .I am totally confused please help me understand this.Respond me to this e mail with your answers norman_g40@yahoo.com

#26 anusuya on 04.18.08 at 10:51 am

Is there any free bug tracking tool apart from bugzilla for .net applications

#27 George on 04.18.08 at 12:00 pm

@anu
QEngine issue manager is another good one
Enjoy…

#28 prasad D.L on 04.23.08 at 8:37 am

hai
I to worked on data synchronize, but i checked with different option like update, insert, and delete and checked data sync is proper on server side. Plz tell me other than this any test can be done on database

#29 How to ask for promotion and salary raise in this appraisal on 04.24.08 at 11:27 am

[...] Ability to find bugs [...]

#30 selvam on 06.11.08 at 1:58 pm

Hi Friends,

Currently i am working in Non-IT field and planned to switch my career to testing.I had learned the basics of testing,and now i am very eager to learn testing practically with real time projects.
If any one interested to teach testing personally with real time projects , i will be more grateful, or else show me the right place in chennai.
Thanks & regards
selvam.ba@rediffmail.com

#31 Ayaskant on 06.27.08 at 12:03 pm

Hi can you please give some example of stress/load test cases,and negative test cases for login screen for performance test.

#32 kiran kumar on 07.15.08 at 10:29 am

HI,
I like to know whether any one have Sample examples for test data

#33 Noman Hamayun on 07.24.08 at 11:38 am

Hi guys, i’ve found this website very very helpfull, i’m new in testing field.
Thumbs up for Vijay, really you’ve done a great job and have explained things in a lay man language which straight a way go into the mind.

Thanks

#34 DevAnand B on 10.01.08 at 6:50 am

Hi Test Professionals,

I wanna some tips to prepare standard ie… industry accepted Test data… wats the basic principleto kept in mind for creating valid test data…

Regards

Dev
Software Test Analyst…

#35 Nilakshi on 12.09.08 at 4:27 am

Hello!
I found this website very helping. Got to know new things
which i would apply in my future project. Thanks.

#36 Nivis on 12.09.08 at 4:16 pm

Hi Vijay,
How can I do system test ( test the effective of many domains and how they impact together) in case my project just enhance and develop some modules. Should I do system test or not ?

#37 Nivis on 12.09.08 at 4:26 pm

Could you explain clearly tip 5. I don’t understand? Pls put example to prove it?
Thanks very much

#38 varun on 12.19.08 at 8:57 pm

Hi guyz n chickz,
dis is varun ur lovin fren frm now onwards, who ever wants any kind of questions testing contexts please carry on and can ask me without second thought.
I noticed one thing in this blog is nobody is responding and noticing all other quests and answers.Please try to focus on all others queries and answers too. Then definitely u wil get 50% answer for ur queries. I’m damn sure about that guyz. i’m wokin in delhi and i’m frm hyd. i have 4yrs backgound in both manual and automation.
So, guys relax on ur back seats.

#39 Ghusadu on 02.24.09 at 11:10 am

fvbvdfbfbfbfb

#40 Navneet Gupta on 05.25.09 at 6:08 pm

Hi Every One,
Hope All for R Good.
I’m new in this field. Before t I was a recruiter and done MCA (distance mode)And now done Software testing so can I have any good job……

And any one have notes on QTP, Win runner and Rational
and Sample Question plz send on my mail ID if any one have.

Thanks in advance
Navneet Gupta
Mail2navneetgupta@gmail.com

#41 Navneet gupta on 06.26.09 at 11:59 am

Hi,
Any one have knowledge of bug reporting and bug tracking.How these are written any one who tell me plz yar kabhi to help kar deya karo…………

mail2navneetgupta@gmail.com

#42 Arvind Gupta on 07.17.09 at 8:56 am

yes, these testing tips is very useful for the mannual tester. thanx buddy

#43 RAJ on 12.05.09 at 12:18 pm

Wear cap of different users while testing respective modules—-Is a good quote.All testers Pl keep this in your minds always.

Thanks buddy.

#44 gokul on 12.09.09 at 6:08 am

hi guys,i got a job in java testing.but actually i don know wat s testing,? how to start test?the applications. what and all want to check in the applications.
i feel ur websites good so m expecting answers for my quries. plzzzzzzzz.. because here i m suffering lot

by,
gokul

#45 Darshana on 12.17.09 at 5:08 am

Hi,

This is darshana i m giving my ISTQB exam on 20th Dec preparation IS ALMOST DONE BUT STILL IF ANYONE COULD SEND ME SOME USEFUL MATERIAL I WOULD BE REALLY THANKFUL

#46 Darshana on 12.17.09 at 5:13 am

HI
varun ,

I have jus got placed in a company i m a fresher and relly want to go into QTP jus let me how to work out things to go into automation. I need to do more of training part in this organization which m not enjoying
jus guide as to wat should i do

Thanks
Darshana

#47 Nishant on 12.23.09 at 11:21 am

“I was intrigued by your website because it seems you are truly passionate and interested in testing. In my organization, we’ve found that it’s really hard to keep the GOOD testers in testing. Many of the really skilled testers are always looking for change and want to get out of testing for some reason. I would love to hear if you have any ideas on how to keep the good testers in testing?”
It’s appraisal time! Many companies conduct periodic reviews to give feedback on performance to their employees and to assist employees in developing their career. This appraisal period may be of six months or one year depending on company policies. Performance appraisal is the right time to ask for your promotion as well as salary raise.

#48 Nishant on 12.23.09 at 11:22 am

Regards,
Nishant Kataria,
QA Engineer.
Chandigarh.

#49 Nishant on 12.23.09 at 11:23 am

Share ur views on
Nishantmca07@gmail.com

#50 jack on 12.24.09 at 7:27 am

hi….
can any one tell me what is imp???
understanding the application or testing module by module …

#51 nidhi on 01.05.10 at 6:20 am

hi…
i would like to know how to write the testcases.would like to know more on testing..

#52 Chida on 03.14.10 at 1:27 pm

What is Front End Testing, Back End Testing, Web Testing, Tracability Matrix?
How to do Front End Test, Back End Testin?

#53 Chida on 03.14.10 at 1:28 pm

What is Front End Testing, Back End Testing, Web Testing, Tracability Matrix?
How to do Front End Test, Back End Testing?

#54 What is the Best Way to Make Developer and QA Relationship Healthy? — Software Testing Help on 07.01.10 at 6:32 pm

[...] a tester, you find the defects but it’s always good to share some tactics with developers on how to test the application.  [...]

#55 vigneshbabu on 08.25.10 at 10:03 am

i am a beginner in software testing? what steps i want to do?can u tell about software tools for Asp.net?i want complete details about software testing

#56 vigneshbabu on 08.25.10 at 10:04 am

tell about software testing tools

#57 grk on 12.03.10 at 11:46 am

hi,
i am fresher ,i’m unable to find lot many bugs by executing test cases…how to find bugs without executing test cases? can anyone send answer to my mailid

#58 grk on 12.03.10 at 11:47 am

krthkgr@gmail.com

#59 Vinay on 12.16.10 at 4:33 pm

I am currently doing a job as a software tester, is doing MBA in IT help me in future.

Thank You

#60 Uma on 01.04.11 at 12:48 pm

I am working as test engineer.but i am not able report many bugs.what can i do??

#61 Vishu on 03.09.11 at 9:45 am

I am fresher for Web based application testing … If u have good tips that will helps for my testing . Plz forword to my Email Id.M No- 9686648874.

#62 Abhay Kumar on 03.11.11 at 7:21 am

Hi All,

Is any one can tell me, how to test the mobile application by manual & automation process?? Is there any method or process without writing test case can automation test??

Is any one can explain about Linear Framework, Keyword Framework, Data-driven & Hybrid Frame work?? What is the difference between them?

Please let me know; if possible kindly mail me at om.abhii@gmail.com with example.

Thanks with Advance.

#63 Abhay Kumar on 03.11.11 at 9:41 am

Hi All,

Is any one can tell me, how to test the mobile application by manual & automation process?? Is there any method or process without writing test case can automation test??

Is any one can explain about Linear Framework, Keyword Framework, Data-driven & Hybrid Frame work?? What is the difference between them?

Please let me know; if possible kindly mail me at om.abhii@gmail.com with example.

Thanks with Advance.

#64 maheswarareddy on 04.17.11 at 10:31 am

new for testing

#65 maheswarareddy on 04.17.11 at 10:32 am

testing

#66 jagan on 06.04.11 at 6:56 am

hi dis is jagan present which computer course better. alredy i hav done oracle,testing tools. but i forgot some subject. so i need a some suggestions to me. pls can any one send me to my email id.

regards

jagan

#67 Gurumurthy on 06.21.11 at 9:20 am

Really awesome example which were presenting here and make people to recall whenever they are need.. I will saying that to one and all working on this website also thank you to posted good example to explaining to end user prospective..

#68 Tal.E on 08.25.11 at 12:12 pm

You should always test like you’re trying to break the application – otherwise you’ll get bored pretty soon. There should be a never ending contest between developers and testers. and when both sides are competitive enough (and have fun in the process), you know you can sleep well at night after releasing a new version.

#69 dhara on 09.12.11 at 12:13 am

Hi,

I have just started to take a knowledge on testing.
This site is very helpful to know in detail about it.

Thaking you for that.

#70 Ajay on 11.14.11 at 12:04 pm

Hi Vinay,

Testing itself is emerging profession.Once you will have some experience you can enter in some big companies and can get make good money.Rather then doing MBA enhance your skill in software testing learn automation,know more about automation tool.
By the way this site is very good for communicating with software tester.

Thanks!!!!
Cheers..

#71 Ajay on 11.14.11 at 12:20 pm

Hi All,

Antivirus testing is also awesome..please do no hesitate to ask about antivirus testing……….

#72 velusamy.s on 01.10.12 at 7:30 am

how to contact the white box testing in application

#73 palak Choudhary on 02.06.12 at 7:39 am

hi.
I have joined a company few months back.I am a fresher.
i am in a project that started 2 years back and there is no documentation as such.
and i do testing on what ever kt i have received.
i havn’t written any test case and test scenarios.

please advise.
What should i do.?
Is this the right way to make my career in testing.??

#74 Top 20 practical software testing tips you should read before testing any application | K Base on 02.10.12 at 9:12 am

[...] If you test the application by intention of finding bugs you will definitely succeed to find those subtle bugs [...]

#75 sandhya on 02.24.12 at 10:23 am

hi
i joined recently in one company u r artical is use full for me please send me articals on testing on a fox pro application

#76 vidhya on 04.01.12 at 1:56 am

Hi,

We have started manual testing & started writing test case using Hp quality center 10.0 tool.

Can you please send me an article based on manual testing & how to use hp quality center tool in depth.

Thanks in Advance.

#77 jani on 06.05.12 at 2:46 pm

Now i have clear idea about the role of Tester.

#78 shamshu on 08.01.12 at 11:19 am

Hi, All friends.
Can anyone suggest me how to write a standard test scenario for an application and how to perform stress test on an application.

Thanks in adv dear

#79 Dipali on 10.04.12 at 8:32 am

Hi,

I have the knowledge of C#.NET. Currently I am working as a manual tester & I want to switch to automation. Can u suggest me what I have to do for that?

Thanks

#80 Dipali on 11.08.12 at 1:15 pm

Hi,

I have the knowledge of C#.NET. Currently I am working as a manual tester & I want to switch to automation. Can u suggest me what I have to do for that?

Thanks

#81 vijay on 12.26.12 at 4:33 pm

im hv newly joining as software tester ….i want to know how to write proper test cases and bug report pls suggest me guys

#82 vijay on 12.26.12 at 4:34 pm

my id is shah786.vijay@gmail.com pls help me

#83 priya on 01.02.13 at 11:20 am

Hi i read all the above comments.. so thought u will be able to help me out.
i am working for SAP ERP HR solutions regression testing. we have some standard applications. how can we find bugs there .. also suggest me some testing methods like exploratory testing so that we can include in regular test cycles to find more bugs. and also i would like to know about monkey testing and free style testing

Regards,
Priya

#84 spandana on 01.21.13 at 12:56 pm

would anyone pls help me to know the data regarding this question in project development

literature survey for the project finding bugs in dynamic web applications

#85 Suhas M on 02.26.13 at 1:07 pm

How do i measure current skillset i possess as a tester and improvise my skills over time.

#86 dimpi on 04.24.13 at 6:49 am

can you send me complete detail about “how we find bugs in an application” manually..my email id is dimpi.jaat@gmail.com

#87 jags on 04.24.13 at 3:13 pm

hello all,
This was a fun article, loved it .

Testing is my passion and i love my job.

Would you guys suggest some more tactics about how to break an application(web based) , with more bugs

#88 Rakshit Jain on 04.28.13 at 5:10 pm

hi,
i am recently doing training in manual testing. Plz tell me how to find bugs ina wesite especially in e-commerce sites..plz help..my mail id is
jain.raksh25@gmail.com

#89 Prasanthi Konijeti on 07.03.13 at 10:25 am

Hi sir,thanks for posting relevant data.
As a software tester[fresher][manual] how to improve testing skills to make my name in an company and some tips to test all testing methods [validations,performance,functionality so on...] and some tools which is helpful for manual tester.

#90 eliyasabu on 09.08.13 at 8:30 am

Hi,
could you please teach me some simple test to learn how to bug .basically i am from other background doesn’t know anything about bugging but i am very much interested t learn please
Thanks
regards
Eliyasabu

#91 Pooja Deshmukh on 10.14.13 at 6:47 am

Hello Vijay Sir ,

Regarding point 8) if you are testing input text box try inserting some html tags as the inputs and see the output on display page.

I have tried this and entered tag in text boxes for name,city etc , it accepts it as a input but on display page it is blank .Can you please advice me ?What should be expected result ?

#92 Hari shankar on 10.19.13 at 5:53 am

@Dipali
check guru99 they have most of the automation tool details

#93 Gokula Rajasekhar on 11.09.13 at 9:53 am

Use Boundary Value Analysis & Equivalence Class Partition for input fields to dig in deeper to find out more bugs & to validate DB..

#94 15 Most Popular Bug Tracking Software to Ease Your Defect Management Process — Software Testing Help on 11.24.13 at 7:39 pm

[…] make the management of these issues simpler and consistent so we can concentrate harder on actually finding more issues in the AUT than managing the ones already […]

#95 A Complete Guide to Usability Testing – It’s Like Trying to Read Minds! — Software Testing Help on 12.23.13 at 5:19 am

[…] testers we know that the earlier a defect is found in the SDLC the cheaper it is to fix it. The same concept holds true for Usability Testing […]

#96 Is Software Testing an Emotional Task? — Software Testing Help on 02.03.14 at 6:52 am

[…] this is how software testing is. Discovering hidden scenarios (which most of the times get revealed when end user use the software) and working towards […]

#97 How to Find Maximum Valid Defects in Any Application? — Software Testing Help on 03.13.14 at 6:28 am

[…] See Also => More tips to find bugs in an application […]

#98 atul on 03.13.14 at 10:42 am

Hi Friends,

I m currently working as a manual tester on desktop application. I m planning to go for an automation testing QTP or Selenium. So plz guide me right track to make a move forward and any comfort institute where I can join n get done the above courses. Plz Plz help me out……..

Thanks and Warm Regards……Tc guyzzzzz

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