SSC CGL Coding-Decoding Questions 2026 — Free Chapter Wise Practice Test

Coding-Decoding Practice Tests — Pick a Level and Start

Tap a level to see every test in it. Level 1 is set at real SSC CGL difficulty — start there the day you finish the concept. Level 2 is pitched above the exam, to push accuracy under pressure.

Coding-decoding is a chapter of rules hidden in an example. A word, number or sentence is written in code, and the example given beside it tells you exactly how. Once you can see the rule — a letter shift, an opposite letter, a key read from coded words, a number formula, codes shared between sentences or a row-and-column position in a matrix — every question becomes mechanical.

Marks are lost in three places. The first is stopping after one step — many codes reverse a word and shift it, and an option that does only one of the two is always there to catch you. The second is losing count past Z — after Z comes A again, so Y + 3 is B. The third is trusting the first or last letter — options are made to differ in a single middle letter, so decode every position before you choose.

How Many Coding-Decoding Questions Are Asked in SSC CGL?

Coding-decoding gives two to three questions in a typical Tier I shift and a few more in Tier II Paper I, which makes it one of the four biggest reasoning chapters along with analogy, classification and series. Most questions take under a minute once the rule is spotted.

The first three forms are seen most often in SSC CGL papers; the rest appear in CGL, CHSL and MTS shifts and in Tier II. Practise all of them so no format surprises you.

What You Will Practice in the Coding-Decoding Chapter

Letter coding

• Uniform shift forward or back, including counting round past Z, and finding the shift from one coded pair
• Alternating, growing, mirrored and repeating shifts — +1, +2, +3 …, +2/−2, odd numbers, cycles of three
• Opposite letters (A↔Z, B↔Y), reversal, swapped halves and pairs, letters sorted into A–Z order
• Two rules chained — reverse then shift, opposite then +1, pair-swap then mirror — and vowel / consonant conditions

Keys, numbers and sentences

• Letter-to-letter and letter-to-digit keys from one or two words, codes written backwards, “which code is not right”
• The code of one letter from jumbled codes of two or three words
• Place-value strings (plain, reverse, doubled, ± position) and a word turned into one number
• Sentence coding with numbers or code words, substitution chains and statement sufficiency

Symbols, matrices and conditions

• Symbol coding for letters and digits, and two-stage symbol → digit → letter codes
• Key tables, letter-cluster and letter-number analogies
• Two-matrix and single-matrix row-column coding — find the set, the set that is not right, decode a set, count the codes
• Rule tables with conditions on the first and last letters, number-to-number codes, two-part codes and step-by-step instructions

Rules worth knowing by heart

Write place values under the word and its code before anything else — the differences show the rule at once.

The three mistakes that cost the most marks

• Applying only one of two steps. If the code is reversed and shifted, the option that is only shifted is always offered.
• Losing count past Z. X + 5 is C, not “off the end” — count round the circle.
• Assuming a matrix is numbered 0–4 and 5–9. Rows or columns may run backwards or the two grids may be swapped — always read the label.

Solved Examples — SSC CGL Coding-Decoding Questions

How the Coding-Decoding Chapter Tests Work

• 25 questions per test, with a full question palette — answered, skipped, marked for review, not visited.
• Every question type in every level — the formats of this chapter are spread across the tests so no pattern is missed.
• Matrix questions as clear figures — both grids with their row and column numbers, exactly as they appear in the exam.
• Optional 15-minute timer — with the clock to build exam speed, without it while you are still learning the chapter.
• Marking: +2 correct, −0.5 wrong, 0 unattempted — the same scheme as the real paper.
• Solutions, shortcut tricks and concept notes open after you submit, question by question — every wrong option is explained too.
• English and हिंदी, chosen at the start of every test.
• Free with a TrickySSC account — sign in once with Google or your mobile number, and every test is open to you.

How to Prepare Coding-Decoding for SSC CGL

1. Learn the place values and opposite pairs. EJOTY (5, 10, 15, 20, 25) and “pairs add to 27” turn every letter question into simple arithmetic.
2. Write the differences under the example. Place values of the word and of its code, one under the other — the shift pattern is visible at once.
3. Check the order of the letters before the letters themselves. If the code’s letters are the word’s letters shuffled, look for a reversal or a swap first.
4. For keys and sentences, work in pairs. Compare two words or two sentences at a time and fix the shared item first.
5. Decode backwards. Undo the last step first — and code your answer forward once to confirm it.
6. Do Level 1 untimed first, then with the 15-minute clock. Move to Level 2 once Level 1 is steady, and then check yourself on a previous year paper.

Related SSC CGL Reasoning Chapters

Coding-decoding shares its skill — working with letter places and patterns — with letter analogy, mixed analogy, series and the alphabet test. Practising them together makes each one faster.

All SSC CGL Chapter Wise Tests

Every chapter below has its own free Level 1 and Level 2 tests with full solutions.

SSC CGL Coding-Decoding Questions — Frequently Asked Questions

More Free SSC CGL Practice